The present invention provides a power storage participation power system voltage control method and a device. The method comprises a step of monitoring the voltage of an energy storage power station control point, when the voltage deviation absolute value of the control point exceeds a threshold value, the voltage is controlled according to the following mode until the voltage deviation absolute value of the control point is smaller than the threshold value: determining a total reactive power adjustment requirement according to a voltage deviation condition, determining total reactive power positive and negative adjustment margins according to a dynamic reactive power adjustment margin, correcting a total reactive power adjustment requirement according to the total reactive power positive and negative adjustment margins, determining a total reactive power command value according to the corrected total reactive power adjustment requirement, distributing the total reactive power command value to each energy storage battery according to a power factor and changing the reactive power output of each energy storage battery, and changing the voltage of the control point through changing the reactive power output of each energy storage battery. By using the method, the power system voltage can be adjusted by an energy storage power station, and the active power output of the energy storage power station is not affected while the power system voltage is controlled.